I love the new series, but I was never able to get into the original series, mainly because they're not in syndication here in the US... If you can't watch them chronologically, they don't make much sense.

This guy Patrick Troughton played the Doctor between 1966 and 1969. Honestly, most of his stories were not much more than excuses to have the Doctor and his friends land on a cardboard planet and fight rubber monsters. It was very much a kiddies show back then. Still, there was something magical about Troughton's performance that in my opinion is still entertaining today. [link]

Honestly, you're not missing much. Most of the Troughton serials are very simplistic cardboard-monster-of-the-week deals. The Mighty Trout himself was a fantastic actor, though. He had the magical ability to turn almost any story, no matter how ridiculous, into compelling entertainment.